Well husband changed the oil sensor about a month ago and changed the oil about 2 weeks ago and just yeserday the light went crazy and ever since he changed the sensor oil has been really burning and smelling really bad. With 192,000 miles on her hopefully the valves arent getting bad. So darth and everyone is my sxt in for new valves. I want my sxt to at least last for another yr or two. I will probably have to have her engine rebuilt or put a 05 engine in.

 

It would be more like new rings. A compression test will tell you if it is bad rings and a leakdown test will tell you if it is valves.

For the compression test, make sure the engine is warm and that the throttle stays in the WOT position the during the entire test (wire it open). You can then put a teaspoon of oil in the cylinder through the spark plug hole. If the reading comes up, then the rings are worn (this may work for all or just one or two cylinders).

 

a leakdown test wont tell you anything other that if the valves are open or closed in relation to the valve seats. it wont tell if your stem seals are leaking. do you notice a puff of blue on first startup then goes away? that would be a sign of stem seals leaking, this wouldnt require new valves just new stem seals.

have you had a recent E-test done? the results should tell you if your burning oil.

Datrths tip for comp test is spot on for determining if rings are bad, bad rings will burn oil all the time unlike stem seals that usually only burn oil on startup.

make sure PCV system is working and PCV is clean(rattles when shaken) as if PCV is plugged it will increase crancase pressure and force oil up past the rings from the crankcase.

BTW high mileage oil will swell seals causing them not to leak as well as heavier weight oil will less likely blow by. next oil change use 10W30 high mileage oil and see if it helps and if its not too cold in your area you may consider 20W50 racing oil

 

No smoke at all when I start her up and I just smell oil burning not everytime but most of the time when Im driving her around and the oil light only comes on once in a great while. Yeah I will use high mileage oil next oil change and 10w30 I can use not racing oil seeing it gets pretty cold here now. So cold she wont start lucky I have a battery I use to jump start her in the mornings when its really cold. THanks you two. Sounds like it could be the pvc being plugged or need new rings.

 

Is it leaking around the oil sending unit? Usually when problems start after replacing something it's the first place you look.

 

Thank you for clearing that up. I've never truly understood what a leakdown test did; I just knew it was something for the valves. It's one thing I've not had to do.

Instead of 20W50, why not a straight 30? I've had better luck with 30 than 20W50 in my older truck. I know many others with heavy equipment and such in the same boat.